CN110582643A

CN110582643A - scroll compressor having a discharge port

Info

Publication number: CN110582643A
Application number: CN201880026948.0A
Authority: CN
Inventors: 崔龙揆; 崔重善; 金哲焕
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2017-04-24
Filing date: 2018-03-30
Publication date: 2019-12-17
Anticipated expiration: 2038-03-30
Also published as: WO2018199488A1; KR102318124B1; CN110582643B; KR20180119054A

Abstract

The scroll compressor of the present invention includes: a first scroll including a first end plate portion having a support hole formed at a center portion thereof through which the rotating shaft passes, and a discharge port formed at a periphery of the support hole, and a first spiral portion formed to protrude from one side surface of the first end plate portion; and a second scroll including a second end plate portion and a second scroll portion, the second end plate portion having a rotation shaft coupling portion formed at a center portion thereof so as to be eccentrically coupled to a rotation shaft penetrating a support hole of the first scroll, the second scroll portion being formed to protrude from one side surface of the second end plate portion and to engage with the first scroll portion to form a compression chamber, the first scroll portion having a limited range of a stiffness coefficient defined as 0.005mm or more, the stiffness coefficient being defined by dividing a height of the scroll portion of the first scroll portion by a thickness of the scroll portion and multiplying the value by an inverse number of a value of a curvature radius of the first scroll portion. Therefore, the deformation of the wrap portion can be suppressed to prevent the friction loss and the wear, and the damage of the wrap portion can be prevented.

Description

Scroll compressor having a discharge port

Technical Field

The present invention relates to a scroll compressor, and more particularly, to a scroll compressor having a compression part disposed on one side of a transmission part.

Background

a scroll compressor is a compressor in which a plurality of scrolls are engaged to perform a relative orbiting motion, and a compression chamber including a suction chamber, an intermediate pressure chamber, and a discharge chamber is formed between the scrolls on both sides. Such a scroll compressor can obtain a relatively high compression ratio as compared with other types of compressors, and can obtain a stable torque since suction, compression, and discharge strokes of refrigerant can be smoothly performed. Therefore, the scroll compressor is widely used for refrigerant compression in an air conditioner or the like. Recently, a high efficiency scroll compressor which reduces an eccentric load and has an operation speed of 180Hz or more has been proposed.

The scroll compressor may be classified into a low pressure type in which a suction pipe is communicated with an inner space of a housing forming a low pressure portion, and a high pressure type in which a suction pipe is directly communicated with a compression chamber. Thus, in the low pressure type, the driving portion is provided in the suction space as the low pressure portion, whereas in the high pressure type, the driving portion is provided in the discharge space as the high pressure portion.

Such a scroll compressor can be classified into an upper compression type and a lower compression type according to the position of a driving part and a compression part. The upper compression type is a type in which the compression portion is located above the driving portion, and the lower compression type is a type in which the compression portion is located below the driving portion.

A scroll compressor generally receives a gas pressure as a pressure of a compression chamber rises toward a direction in which a orbiting scroll is away from a fixed scroll. Therefore, the orbiting scroll leaks between the compression chambers while being away from the fixed scroll to increase a compression loss.

Therefore, in the scroll compressor, a top seal method in which a seal member is inserted into the tip end surfaces of the fixed scroll and the orbiting scroll, or a back pressure method in which a back pressure chamber for forming an intermediate pressure or a discharge pressure is provided on the back surface of the orbiting scroll or the fixed scroll, and the pressure of the back pressure chamber is used to pressurize the orbiting scroll or the fixed scroll to the opposite side scroll is applied.

in particular, in the back pressure system, a system is known in which a seal member is provided between a back surface of the orbiting scroll (or a back surface of the fixed scroll) and a corresponding frame, and a back pressure chamber is formed inside or outside the seal member. In this type of back pressure method using a seal member, an annular groove is formed in one member constituting a thrust surface, and a seal member having a quadrangular cross-sectional shape is inserted into the annular groove. Thus, when the compressor is operated, the intermediate-pressure refrigerant compressed in the compression chamber flows into the annular groove, and the seal member is floated and attached to the opposite member by the intermediate-pressure refrigerant, thereby forming the back pressure chamber.

However, in the conventional scroll compressor as described above, as the discharge port is formed in the center portion of the fixed scroll, the back pressure and the gas pressure received in the center portion of the fixed scroll portion and the orbiting scroll portion are greater than those received in the edge portion, and thus the center portion of the fixed scroll portion or the orbiting scroll portion is bent and deformed toward the edge portion, and a severe friction loss or abrasion occurs between the fixed scroll portion or the orbiting scroll portion and the scroll facing the fixed scroll portion or the orbiting scroll portion, thereby lowering the compressor efficiency.

In the conventional scroll compressor as described above, when the so-called shaft penetrating scroll compressor in which the rotation shaft and the compression chamber are radially overlapped is used, the rotation shaft penetrates and is coupled to the center portion of the fixed scroll, and the discharge end of the fixed scroll portion cannot sufficiently extend to the center portion of the fixed scroll due to the rotation shaft, so that the rigidity of the discharge end of the fixed scroll portion is weakened, and the fixed scroll portion can be severely bent or even the discharge end of the fixed scroll portion can be broken. Further, as disclosed in korean patent laid-open publication No. 10-1059880, when the fixed scroll and the orbiting scroll are changed in an atypical shape to increase the compression ratio of the compression chamber, the discharge end of the fixed scroll is more severely deformed, thereby causing a risk of breakage. In the case where a projection is formed at the discharge end of the fixed scroll part to increase the scroll support force, the scroll part deformed with an increase in the compression ratio cannot be completely suppressed, and the reliability of the compressor is lowered due to friction loss, wear, or rupture of the scroll.

In the conventional scroll compressor described above, as disclosed in japanese laid-open patent publication No. 2000-257573, deformation or breakage of the wrap (particularly, the fixed wrap) is suppressed by changing the shape of the wrap. However, when the root of the wrap portion is formed thick as described above, the same groove should be formed also at the tip of the wrap portion of the facing scroll, and therefore, not only the manufacturing process of the wrap portion becomes complicated by the thickness, but also the thickness of the wrap portion between the middle of the wrap portion and the tip of the wrap portion becomes thin, and there is a limit that deformation or rupture of the wrap portion cannot be solved.

to this end, when the entire thickness of the scroll portion is increased, the size of the scroll is increased to increase the size of the compressor or conversely, the radius of gyration is decreased to decrease the volume of the compression chamber in order to secure the radius of gyration. The problem that occurs is that the wrap shape is arbitrarily changed without specifically considering the rigidity of the wrap.

Disclosure of Invention

problems to be solved by the invention

An object of the present invention is to provide a scroll compressor in which the rigidity of the discharge end of the scroll portion is optimized to prevent the discharge end of the scroll portion from excessively adhering to the end plate portion of the facing scroll and causing friction loss or wear.

Another object of the present invention is to provide a scroll compressor in which the rigidity of the discharge end of the scroll portion is optimized to suppress the vicinity of the discharge end of the scroll portion from being excessively deformed and broken.

It is another object of the present invention to provide a scroll compressor in which the rigidity of the discharge end of the fixed scroll is optimized to prevent the discharge end of the fixed scroll from being excessively deformed or broken even when the rotation shaft penetrates the fixed scroll and radially overlaps the compression chamber, thereby improving the efficiency and reliability of the compressor.

Means for solving the problems

In order to achieve the object of the present invention, a scroll compressor in which the discharge side rigidity of a scroll portion formed in one of two members that slide with each other is optimized to prevent the scroll portion from being excessively deformed or broken can be provided.

In this case, the rigidity of the wrap portion may define a range of rigidity coefficients defined based on the height and thickness of the wrap portion and the radius of curvature.

The stiffness coefficient may be determined by the inclination of the wrap portion × wrap load by air pressure + an optional value.

Another object of the present invention is to provide a scroll compressor including: a first scroll part having a discharge end at a central portion thereof and a suction end at an edge portion thereof, the first scroll part being formed by connecting a plurality of curved lines between the discharge end and the suction end; and a second scroll part having a discharge end at a center portion thereof, a suction end at an edge portion thereof, a plurality of curved lines connecting the discharge end to the suction end, and a rotation shaft coupling portion at the discharge end so that a rotation shaft overlaps and couples with the first scroll part, the second scroll part engaging with the first scroll part and performing a revolving motion with respect to the first scroll part to form a compression chamber moving toward the center portion together with the first scroll part, wherein a specific section of at least one of the first scroll part and the second scroll part is formed by a stiffness coefficient defined as follows: the average height of the wrap portion in the specific section is divided by the average thickness of the wrap portion to obtain a first value, the first value is multiplied by the average radius of curvature of the wrap portion to obtain a second value, and the inverse of the second value is used to define the stiffness coefficient.

Wherein the limited range of the rigidity coefficient is more than the limit limited range defined by [ (0.0001-0.0003) x scroll load (N) + (7.0000-8.0000) ].

the limit range is defined by [0.0002 × wrap load (N) +7.5202 ].

When the center portion side of the first scroll portion is set as a discharge end and the discharge end is set as 0 ° with reference to the rotation angle of the rotation shaft, the specific section is in a range of 0 to 45 ° with reference to the rotation angle of the rotation shaft.

a circular arc compression surface is formed on one side of the rotation shaft coupling portion, a depressed portion in which the thickness of the second spiral portion is reduced is formed in a section between the circular arc compression surface and the outer side surface of the rotation shaft coupling portion, a protruding portion that engages with the depressed portion of the second spiral portion is formed in a section near the discharge end of the first spiral portion, and at least a part of the section in which the protruding portion is formed satisfies the range of the stiffness coefficient.

Another object of the present invention is to provide a scroll compressor including: a first scroll including a first end plate portion having a support hole formed at a center portion thereof through which the rotating shaft passes, and a discharge port formed at a periphery of the support hole, and a first spiral portion formed to protrude from one side surface of the first end plate portion; and a second scroll including a second end plate portion and a second scroll portion, the second end plate portion having a rotation shaft coupling portion formed at a center portion thereof so as to be eccentrically coupled to a rotation shaft penetrating a support hole of the first scroll, the second scroll portion being formed to protrude from one side surface of the second end plate portion and to be engaged with the first scroll portion to form a compression chamber, the first scroll portion having a stiffness coefficient defined within a range of 0.005mm or more, the first scroll portion having a height divided by a thickness of the scroll portion, and the stiffness coefficient being defined by an inverse number of a value obtained by multiplying the value by a curvature radius of the first scroll portion.

wherein the defined range of the stiffness coefficient is defined for a section between any two points in the first wrap along the travel direction of the wrap, and the wrap height, wrap thickness, and wrap curvature radius are defined by an average wrap height, average wrap thickness, and average wrap curvature radius of the corresponding section.

The limited range of the stiffness coefficient is defined for any point in the first scroll part, and the scroll part height, the scroll part thickness, and the scroll part curvature radius are defined by the scroll part height, the scroll part thickness, and the scroll part curvature radius at the corresponding point.

In a section from an end portion of the first scroll portion adjacent to the discharge port to a certain point or in a certain point of the section, the limited range of the stiffness coefficient is not less than a limit limited range defined by [ (0.0001 to 0.0003) × scroll portion load (N) + (7.0000 to 8.0000) ].

Another object of the present invention is to provide a scroll compressor including: a cover body storing oil in an internal space; a driving motor disposed in the inner space of the cover; a rotating shaft coupled with the driving motor; a frame provided at a lower side of the driving motor; a first scroll provided at a lower side of the frame, having a first scroll portion formed at one side surface thereof, having a support hole formed at a center thereof through which the rotary shaft passes, and having a discharge port formed at a periphery of the support hole; and a second scroll in which a second scroll portion meshing with the first scroll portion is formed, the rotary shaft being eccentrically coupled to the second scroll portion so as to radially overlap the second scroll portion, the second scroll orbiting relative to the first scroll portion to form a compression chamber with the first scroll portion; and a seal member provided between the frame and the second scroll, the seal member separating an interval between the frame and the second scroll into an inner interval as a center portion side and an outer interval as an edge side so that oil sucked up by the rotary shaft flows into the inner interval to form a back pressure chamber, the first wrap being formed such that a limit range of a stiffness coefficient defined as follows is 5 or more, the stiffness coefficient being defined by dividing an average wrap height by an average wrap thickness between an end portion of one side adjacent to the discharge port in the first wrap and a first point, and multiplying an inverse number of a value obtained by multiplying the value by an average wrap curvature radius by an arbitrary value 1000 mm.

The limit range is defined by [0.0002 × wrap load (N) +7.5202 ].

The first point is a point within a range of 0 to 60 ° with respect to the rotation angle of the rotation shaft, where the center portion side of the first scroll part is set as a discharge end and the discharge end is set as 0 ° with respect to the rotation angle of the rotation shaft.

A circular arc compression surface is formed on one side of the rotation shaft coupling portion, a recessed portion in which the thickness of the second spiral portion is reduced is formed in a section between the circular arc compression surface and the outer side surface of the rotation shaft coupling portion, a protruding portion that engages with the recessed portion of the second spiral portion is formed in a section near the discharge end of the first spiral portion, and at least a part of the section in which the protruding portion is formed satisfies the limited range of the stiffness coefficient.

Effects of the invention

The scroll compressor of the present invention can prevent the wrap from excessively adhering to the facing scroll by optimizing the rigidity of the wrap in the portion near the discharge end of the fixed wrap or the orbiting wrap to minimize the deformation of the wrap at the discharge end on the center portion side which is subjected to relatively high back pressure and air pressure, thereby improving the compressor efficiency by reducing the friction loss or wear between the scrolls.

further, by optimizing the rigidity of the wrap portion of the portion adjacent to the discharge end of the fixed wrap portion or the swirl wrap portion, the central portion side discharge end of the fixed wrap portion or the swirl wrap portion is suppressed from being bent outward in the radial direction, thereby suppressing leakage in the compression chamber to improve the compression efficiency, and suppressing breakage of the wrap portion to improve the reliability of the compressor.

In addition, even when the rotation shaft penetrates the center of the fixed scroll and the discharge end of the fixed scroll is spaced apart from the center of the fixed scroll, friction or abrasion between the fixed scroll and the scroll or deformation or breakage of the fixed scroll can be prevented by optimizing the rigidity of the lap portion in the portion near the discharge end, and the efficiency and reliability of the compressor can be improved.

Drawings

Fig. 1 is a longitudinal sectional view showing a lower compression type scroll compressor of the present invention.

Fig. 2 is a transverse sectional view showing the compression part in fig. 1.

Fig. 3 is a front view showing a part of the rotary shaft for explaining the sliding portion in fig. 1.

Fig. 4 is a longitudinal sectional view shown for explaining an oil supply passage between the back pressure chamber and the compression chamber in fig. 1.

Fig. 5 is a schematic view showing a deformation amount of the discharge end peripheral portion of the first scroll portion by analyzing the portion in the scroll compressor in fig. 1.

Fig. 6 is a schematic view showing the shape of the wrap portion in the portion having the largest deformation amount in fig. 5 in front.

fig. 7 is a schematic view for explaining the specification of the discharge end of the scroll portion according to the present embodiment.

Fig. 8 is a graph for analyzing the amount of wrap deformation based on various specifications and operating speeds of the first wrap.

fig. 9 is a cross-sectional view showing the amount of deformation of the discharge end of the wrap portion having a limited range of the rigidity coefficient of the wrap portion of the present embodiment, in comparison with the conventional amount of deformation.

Detailed Description

A scroll compressor of the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings. However, for convenience of explanation, a scroll compressor of a type in which a rotary shaft and an orbiting scroll portion are overlapped on the same plane in a lower compression type scroll compressor in which a compression portion is positioned below a transmission portion will be described as a typical example. Scroll compressors of this type are known to be suitable for use in refrigeration cycles under high temperature and high compression ratio conditions.

Fig. 1 is a longitudinal sectional view showing a lower compression type scroll compressor of the present invention. Fig. 2 is a transverse sectional view showing the compression part in fig. 1. Fig. 3 is a front view showing a part of the rotary shaft for explaining the sliding portion in fig. 1. Fig. 4 is a longitudinal sectional view shown for explaining an oil supply passage between the back pressure chamber and the compression chamber in fig. 1.

Referring to fig. 1, in the lower compression scroll compressor of the present embodiment, a power transmission unit 20 that constitutes a driving motor and generates a rotational force is provided inside a housing 10, and a compression unit 30 that receives the rotational force of the power transmission unit 20 and compresses a refrigerant is provided below the power transmission unit 20 with a predetermined space (hereinafter, an intermediate space) 10a interposed therebetween.

The cover 10 may be composed of a cylinder case 11 forming a closed container, an upper case 12 covering an upper portion of the cylinder case 11 and forming a closed container together therewith, and a lower case 13 covering a lower portion of the cylinder case 11 and forming a closed container together therewith and forming an oil storage space 10 c.

A refrigerant suction pipe 15 penetrates through a side surface of the cylindrical shell 11 to directly communicate with a suction chamber of the compression portion 30, and a refrigerant discharge pipe 16 communicating with the upper space 10b of the cover 10 may be provided at an upper portion of the upper shell 12. The refrigerant discharge pipe 16 corresponds to a passage through which the compressed refrigerant discharged from the compression section 30 to the upper space 10b of the cover 10 is discharged to the outside, and the refrigerant discharge pipe 16 can be inserted to an intermediate position of the upper space 10b of the cover 10 to form a kind of oil separation space for the upper space 10 b. Further, an oil separator (not shown) for separating oil mixed in the refrigerant may be provided inside the cover body 10 including the upper space 10b or may be connected to the refrigerant suction pipe 15 in the upper space 10b, depending on the case.

The transmission unit 20 includes a stator 21 and a rotor 22 rotating inside the stator 21. The stator 21 has teeth and grooves formed on an inner circumferential surface thereof in a circumferential direction to form a plurality of coil winding portions (not shown) around which the coils 250 are wound, and a second refrigerant flow path P is formed by a gap between the inner circumferential surface of the stator and the outer circumferential surface of the rotor 22 and the coil winding portions_G2. Thereby, the refrigerant passes through the first refrigerant flow path P described later_G1The refrigerant discharged into the intermediate space 10c between the power transmission unit 20 and the compression unit 30 passes through the second refrigerant flow path P formed in the power transmission unit 20_G2Moves to the upper space 10b formed on the upper side of the transmission part 20.

A plurality of D-cut (D-cut) surfaces 21a are formed on the outer circumferential surface of the stator 21 in the circumferential direction, and a first oil flow path P is formed between the D-cut surfaces 21a and the inner circumferential surface of the cylindrical housing 11_O1And is used for oil circulation. Thereby, the oil separated from the refrigerant in the upper space 10b passes through the first oil flow path P_O1And a second oil flow path P described later_O2Moves to the lower space 10 c.

a frame 31 forming the compression part 30 is provided at a predetermined interval below the stator 21, and the frame 31 is fixedly coupled to the inner circumferential surface of the housing 10. The frame 31 is fixedly joined to the inner peripheral surface of the cylindrical housing 11 by hot pressing or welding the outer peripheral surface thereof.

a frame side wall portion (first side wall portion) 311 having an annular shape is formed at an edge position of the frame 31, and a plurality of communication grooves 311b are formed in an outer peripheral surface of the first side wall portion 311 in a circumferential direction. The communication groove 311b forms a second oil flow path P together with a communication groove 322b of the first scroll 32 described later_O2。

A first support portion 312 is formed at the center of the frame 31, and the first support portion 312 supports a main bearing portion 51 of the rotary shaft 50, which will be described later. A first support hole 312a is formed to penetrate the first support portion in the axial direction, and rotatably inserts the main bearing portion 51 of the rotary shaft 50 and supports the same in the radial direction.

A fixed scroll (hereinafter, referred to as a first scroll) 32 may be provided on a lower surface of the frame 31 via a orbiting scroll (hereinafter, referred to as a second scroll) 33 eccentrically coupled to the rotating shaft 50. The first scroll 32 may be fixedly coupled to the frame 31 or may be movably coupled in the axial direction.

On the other hand, the first scroll 32 has a substantially circular plate-shaped fixed end plate portion (hereinafter, first end plate portion) 321, and a scroll side wall portion (hereinafter, second side wall portion) 322 coupled to the lower surface edge of the frame 31 is formed at the edge of the first end plate portion 321.

A suction port 324, in which a suction chamber communicates with the refrigerant suction pipe 15, is formed through one side of the second side wall portion 322, and discharge ports 325a and 325b, which communicate with a discharge chamber and discharge a compressed refrigerant, are formed in the center portion of the first end plate portion 321. The discharge ports 325a and 325b may be formed in a single body for communication with both the first compression chamber V1 and the second compression chamber V2, which will be described later, or in a plurality of bodies for communication with the compression chambers V1 and V2 individually.

The communication groove 322b described above is formed in the outer peripheral surface of the second side wall portion 322, and the communication groove 322b forms the second oil flow path P for guiding the collected oil to the lower space 10c together with the communication groove 311b of the first side wall portion 311_O2。

The discharge cap 34 may be coupled to a lower side of the first scroll 32, and the discharge cap 34 guides the refrigerant discharged from the compression chamber V to a refrigerant flow path described later. The discharge cap 34 accommodates the discharge ports 325a and 325b in its internal space, and also accommodates the first refrigerant flow path P for guiding the refrigerant discharged from the compression chamber V through the discharge ports 325a and 325b to the upper space 10b of the cover body 10, more precisely, to the space between the power transmission unit 20 and the compression unit 30_G1Of the inlet of (a).

wherein the first refrigerant flow path P_G1The second side wall 322 of the fixed scroll 32 and the first side wall 311 of the frame 31 penetrate in this order from the inside of the flow path separation unit 40, that is, the side of the rotating shaft 50 inside with respect to the flow path separation unit 40. Thus, the second oil flow path P described above is provided outside the flow path separation unit 40_O2And the first oil flow path P_O1And (4) communicating.

A fixed scroll portion (hereinafter, a first scroll portion) 323 may be formed on the upper surface of the first end plate portion 321, and the fixed scroll portion 323 engages with a swirl returning scroll portion (hereinafter, a second scroll portion) 332 described later to form the compression chamber V. The first scroll portion 323 will be described later together with the second scroll portion 332.

Further, a second support portion 326 for supporting an auxiliary bearing portion 52 of the rotary shaft 50 described later is formed in the center of the first end plate portion 321, and a second support hole 326a is formed in the second support portion 326, and the second support hole 326a penetrates in the axial direction and supports the auxiliary bearing portion 52 in the radial direction.

On the other hand, the second scroll 33 may have a substantially circular plate shape with a turning end plate portion (hereinafter, second end plate portion) 331. A second scroll portion 332 may be formed under the second end plate portion 331, and the second scroll portion 332 may be engaged with the first scroll portion 322 to form a compression chamber.

The second scroll portion 332 may be formed in an involute shape together with the first scroll portion 323, but may be formed in other various shapes. For example, as shown in fig. 2, the second scroll portion 332 has a form in which a plurality of circular arcs having different diameters and dots are connected to each other, and the curve of the outermost contour is formed substantially in the form of an ellipse having a major axis and a minor axis. Which is also formed in the same manner at the first wrap portion 323.

A rotation shaft coupling portion 333 constituting an inner end portion of the second scroll portion 332 is formed to penetrate in the axial direction in a central portion of the second end plate portion 331, and an eccentric portion 53 to which a rotation shaft 50 described later is rotatably inserted and coupled to the rotation shaft coupling portion 333.

The outer peripheral portion of the rotation shaft coupling portion 333 is connected to the second scroll portion 332, and functions to form a compression chamber V together with the first scroll portion 322 during compression.

The rotation shaft coupling portion 333 and the second scroll portion 332 are formed at a height that overlaps on the same plane, so that the eccentric portion 53 of the rotation shaft 50 and the second scroll portion 332 can be disposed at a height that overlaps on the same plane. This allows the thrust and the compression force of the refrigerant to be applied to the same plane with respect to the second end plate portion and to cancel each other out, thereby preventing the second scroll 33 from being inclined due to the action of the compression force and the thrust.

The rotating shaft coupling part 333 has a recessed part 335 formed in an outer peripheral part facing an inner end of the first spiral part 323, and the recessed part 335 engages with a projection 328 of the first spiral part 323, which will be described later. An increasing portion 335a, which increases in thickness from the inner circumferential portion to the outer circumferential portion of the rotating shaft coupling portion 333, is formed on one side of the recessed portion 335 on the upstream side along the forming direction of the compression chamber V. Accordingly, the compression path of the first compression chamber V1 immediately before discharge is lengthened, and the compression ratio of the first compression chamber V1 can be increased to be close to the compression ratio of the second compression chamber V2. The first compression chamber V1 is formed between the inner side surface of the first scroll part 323 and the outer side surface of the second scroll part 332, and will be described later in detail with reference to the second compression chamber V2.

The other side of the recess 335 is formed with a circular arc compression surface 335b having a circular arc shape. The diameter of the arc compression surface 335b is determined by the thickness of the inner end of the first scroll portion 323 (i.e., the thickness of the discharge end) and the radius of gyration of the second scroll portion 332, and the diameter of the arc compression surface 335b increases when the thickness of the inner end of the first scroll portion 323 is increased. Accordingly, the thickness of the second wrap portion around the circular arc compression surface 335b is also increased, thereby ensuring durability, and the compression ratio of the second compression chamber V2 can be increased by lengthening the compression path.

Further, a protrusion 328 protruding toward the outer peripheral portion side of the rotation shaft coupling part 333 is formed in the vicinity of the inner end (suction end or start end) of the first scroll part 323 corresponding to the rotation shaft coupling part 333, and a contact part 328a protruding from the protrusion and engaging with the recess 335 is formed in the protrusion 328. That is, the inner side end of the first wrap portion 323 may be formed with a greater thickness than other portions. This improves the strength of the lap at the inner end of the first lap 323 that receives the maximum compression force, thereby improving durability.

On the other hand, the compression chamber V is formed between the first end plate portion 321 and the first scroll portion 323, and between the second scroll portion 332 and the second end plate portion 331. The suction chamber, the intermediate pressure chamber, and the discharge chamber are formed continuously in the traveling direction of the scroll portion.

As shown in fig. 2, the compression chamber V is constituted by a first compression chamber V1 formed between the inner side surface of the first scroll part 323 and the outer side surface of the second scroll part 332, and a second compression chamber V2 formed between the outer side surface of the first scroll part 323 and the inner side surface of the second scroll part 332.

That is, the first compression chamber V1 includes a compression chamber formed between two contact points P11 and P12 formed by the contact between the inner surface of the first scroll portion 323 and the outer surface of the second scroll portion 332, and the second compression chamber V2 includes a compression chamber formed between two contact points P21 and P22 formed by the contact between the outer surface of the first scroll portion 323 and the inner surface of the second scroll portion 332.

At this time, in the first compression chamber V1 immediately before discharge, when α is an angle having a larger value out of angles formed by two lines connecting the center O of the rotation shaft coupling portion, which is the center of the eccentric portion, and the two contact points P11 and P12, respectively, α <360 ° immediately before discharge start, and a distance l between normal vectors of the two contact points P11 and P12 has a value larger than 0.

Accordingly, the first compression chamber immediately before discharge has a smaller volume than the fixed wrap and the orbiting wrap formed by the involute curve, and the compression ratio of the first compression chamber V1 and the compression ratio of the second compression chamber V2 can both be improved without increasing the size of the first wrap 323 and the second wrap 332.

On the other hand, as described above, the second scroll 33 is provided between the frame 31 and the fixed scroll 32 so as to be rotatable, a cross 35 for preventing the second scroll 33 from rotating is provided between the upper surface of the second scroll 33 and the corresponding lower surface of the frame 31, and a seal member 36 for forming a back pressure chamber S1 described later may be provided at an inner position of the cross 35.

Further, an intermediate pressure space is formed outside the seal member 36 through an oil supply hole 321a provided in the second scroll 32. The intermediate pressure space communicates with the intermediate compression chamber V, and functions as a back pressure chamber as the intermediate pressure refrigerant is filled. Therefore, the back pressure chamber formed inside with the seal member 36 as the center may be referred to as a first back pressure chamber S1, and the intermediate pressure space formed outside with the seal member 36 as the center may be referred to as a second back pressure chamber S2. The final back pressure chamber S1 is a space formed on the lower surface of the frame 31 and the upper surface of the second scroll 33 centering on the seal member 36, and the back pressure chamber S1 will be described again together with the seal member described later.

On the other hand, the flow path separation means 40 is provided in the intermediate space 10a, which is a flow space formed between the lower surface of the power transmission unit 20 and the upper surface of the compression unit 30, and serves to prevent interference between the refrigerant discharged from the compression unit 30 and the oil moving from the upper space 10b of the power transmission unit 20 in the oil separation space to the lower space 10c of the compression unit 30 in the oil storage space.

For this reason, the flow path separating unit 40 of the present embodiment includes a flow path guide that separates the first space 10a into a space where refrigerant flows (hereinafter, refrigerant flowing space) and a space where oil flows (hereinafter, oil flowing space). The flow channel guide may be configured to separate the first space 10a into the refrigerant flow space and the oil flow space only by the flow channel guide itself, or may be configured to function as a flow channel guide by combining a plurality of flow channel guides.

The flow path separation unit of the present embodiment is constituted by a first flow path guide 410 provided to the frame 31 and extending upward and a second flow path guide 420 provided to the stator 21 and extending downward. The first flow path guide 410 and the second flow path guide 420 are overlapped in the axial direction to separate the intermediate space 10a into a refrigerant flow space and an oil flow space.

at this time, the first flow path guide 410 is formed in a ring shape and fixedly coupled to the upper surface of the frame 31, and the second flow path guide 420 is formed to extend from an insulator inserted into the stator 21 to insulate the coil winding.

The first flow path guide 410 is constituted by a first annular wall portion 411 extending upward on the outer side, a second annular wall portion 412 extending upward on the inner side, and an annular surface portion 413 extending in the radial direction to connect between the first annular wall portion 411 and the second annular wall portion. The first annular wall portion 411 is higher than the second annular wall portion 412, and a refrigerant through hole may be formed in the annular surface portion 413 to communicate with a refrigerant hole communicating from the compression portion 30 to the intermediate space 10 a.

Weight 26 is provided inside second annular wall portion 412, i.e., in the rotational axis direction, and weight 26 is coupled to rotor 22 or rotational axis 50 and rotates. At this time, counterweight 26 can stir the refrigerant while rotating, but the second annular wall portion 412 can block the refrigerant from moving to the counterweight 26 side, and thus the refrigerant can be suppressed from being stirred by counterweight 26.

The second flow path guide 420 is composed of a first extension 421 extending downward at the outside of the insulator and a second extension 422 extending downward at the inside of the insulator. The first extension 421 is formed to overlap the first annular wall 411 in the axial direction, and functions to separate the refrigerant flow space and the oil flow space. The second extension 422 may not be formed as needed even if the second extension 422 is formed, preferably, it does not axially overlap with the second annular wall portion 412 or an interval should be sufficiently left in the radial direction for sufficiently flowing the refrigerant even if it overlaps.

On the other hand, the upper portion of the rotary shaft 50 is press-fitted into the center of the rotor 22, and the lower portion is coupled to the compression portion 30 and radially supported. Thereby, the rotary shaft 50 transmits the rotational force of the power transmission unit 20 to the swirling coil 33 of the compression unit 30. Thereby, the second scroll 33 eccentrically coupled to the rotary shaft 50 performs a orbiting motion with respect to the first scroll 32.

A main bearing portion (hereinafter, referred to as a first bearing portion) 51 is formed in the lower half of the rotary shaft 50, the main bearing portion 51 is inserted into and radially supported by the first support hole 312a of the frame 31, an auxiliary bearing portion (hereinafter, referred to as a second bearing portion) 52 is formed below the first bearing portion 51, and the auxiliary bearing portion 52 is inserted into and radially supported by the second support hole 326a of the first scroll 32. An eccentric portion 53 may be formed between the first bearing portion 51 and the second bearing portion 52, and the eccentric portion 53 may be inserted into and coupled to the rotation shaft coupling portion 333.

The first bearing portion 51 and the second bearing portion 52 are formed on a coaxial line to have the same axial center, and the eccentric portion 53 may be formed eccentrically in the radial direction with respect to the first bearing portion 51 or the second bearing portion 52. The second bearing portion 52 may be formed eccentrically with respect to the first bearing portion 51.

The eccentric portion 53 has an outer diameter smaller than that of the first bearing portion 51 and larger than that of the second bearing portion 52 to facilitate coupling of the rotating shaft 50 through the respective bearing holes 312a, 326a and the rotating shaft coupling portion 333. However, in the case where the eccentric portion 53 is not formed integrally with the rotating shaft 50 but is formed using an additional bearing, the rotating shaft 50 can be insert-coupled even if the outer diameter of the second bearing portion 52 is not smaller than the outer diameter of the eccentric portion 53.

An oil supply passage 50a for supplying oil to each of the bearing portion and the eccentric portion may be formed in the rotary shaft 50 in the axial direction. As the compression part 30 is located below the power transmission part 20, the oil supply passage 50a is formed as a groove from the lower end of the rotary shaft 50 to a position substantially at the lower end or the middle height of the stator 21 or higher than the upper end of the first bearing part 31, but the rotary shaft 50 may be formed to penetrate in the axial direction, depending on the case.

an oil feeder 60 for drawing out oil filled in the lower space 10c may be coupled to a lower end of the rotary shaft 50, i.e., a lower end of the second bearing portion 52. The oil feeder 60 includes an oil supply pipe 61 inserted into the oil supply passage 50a coupled to the rotary shaft 50, and a blocking member 62 that accommodates the oil supply pipe 61 and blocks entry of foreign matter. The oil supply pipe 61 may penetrate the discharge cap 34 and be immersed in the oil in the lower space 10 c.

On the other hand, as shown in fig. 3, a sliding portion oil supply passage F1 is formed in each of the bearing portions 51 and 52 and the eccentric portion 53 of the rotary shaft 50 to be connected to the oil supply passage 50a and supply oil to each sliding portion.

The sliding portion oil supply passage F1 includes a plurality of oil supply holes 511, 521, and 531 penetrating through the oil supply passage 50a toward the outer peripheral surface of the rotary shaft 50, and a plurality of oil supply grooves 512, 522, and 532 for lubricating the bearing portions 51 and 52 and the eccentric portion 53 by communicating the oil supply holes 511, 521, and 531 with the outer peripheral surfaces of the bearing portions 51 and 52 and the eccentric portion 53, respectively.

For example, the first bearing portion 51 has the first oil supply hole 511 and the first oil supply groove 512 formed therein, the second bearing portion 52 has the second oil supply hole 521 and the second oil supply groove 522 formed therein, and the eccentric portion 53 has the third oil supply hole 531 and the third oil supply groove 532 formed therein. The first oil supply groove 512, the second oil supply groove 522, and the third oil supply groove 532 are each formed in an elongated groove shape elongated in the axial direction or the oblique direction.

Further, a first coupling groove 541 and a second coupling groove 542, which are respectively annular, are formed between the first bearing portion 51 and the eccentric portion 53 and between the eccentric portion 53 and the second bearing portion 52. The first connection groove 541 communicates with the lower end of the first oil supply hole 512, and the second connection groove 542 communicates with the upper end of the second oil supply groove 522, so that a part of the oil that lubricates the first bearing portion 51 by the first oil supply groove 512 flows into the first connection groove 541 to be collected, and the oil flows into the first back pressure chamber S1 to form a back pressure of discharge pressure. The oil that lubricates the second bearing portion 52 by the second oil supply groove 522 and the oil that lubricates the eccentric portion 53 by the third oil supply groove 532 are collected in the second connecting groove 542, and flow into the compression portion 30 through the space between the distal end surface of the rotation shaft coupling portion 333 and the first end plate portion 321.

Then, a small amount of oil sucked in the direction of the upper end of the first bearing portion 51 flows out from the upper end of the first support portion 312 of the frame 31 to the outside of the bearing surface, flows along the first support portion 312 to the upper surface 31a of the frame 31, and then passes through an oil flow path P formed continuously between the outer peripheral surface of the frame 31 (or a groove communicating with the outer peripheral surface from the upper surface) and the outer peripheral surface of the first scroll 32_O1、P_O2Is recovered to the lower space 10 c.

The oil discharged from the compression chamber V to the upper space 10b of the cover 10 together with the refrigerant is separated from the refrigerant in the upper space 10b of the cover 10, and passes through the first oil flow path P formed on the outer peripheral surface of the power transmission unit 20_O1And a second oil flow path P formed on the outer peripheral surface of the compression part 30_O2is recovered to the lower space 10 c. At this time, the flow path separating means 40 is provided between the power transmission unit 20 and the compression unit 30, so that the oil separated from the refrigerant in the upper space 10b and moved to the lower space 10c and the refrigerant discharged from the compression unit 20 and moved to the upper space 10b do not interfere with each other and do not mix with each other, and pass through different paths [ (P) from each other_O1、P_O2)][(P_G1、P_G2)]The oil moves to the lower space 10c, and the refrigerant moves to the upper space 10 b.

on the other hand, a compression chamber oil supply passage F2 is formed in the second scroll 33, and the compression chamber oil supply passage F2 supplies the oil sucked up through the oil supply flow passage 50a to the compression chamber V. The compression chamber oil supply passage F2 is connected to the slide oil supply passage F1 described above.

The compression chamber oil supply passage F2 is constituted by a first oil supply passage 371 communicating between the oil supply passage 50a and the second back pressure chamber S2 forming an intermediate pressure space, and a second oil supply passage 372 communicating with the second back pressure chamber S2 and the intermediate pressure chamber of the compression chamber V.

Of course, the compression chamber oil supply passage may be directly communicated from the oil supply passage 50a to the intermediate pressure chamber without passing through the second back pressure chamber S2. However, in this case, a refrigerant flow path for communicating the second back pressure chamber S2 with the intermediate pressure chamber V needs to be separately provided, and an oil flow path for supplying oil to the cross ring 35 located in the second back pressure chamber S2 needs to be separately provided. This complicates the machining due to the increased number of passages. Therefore, in order to reduce the number of passages by simplifying the refrigerant flow path and the oil flow path, it is preferable that the oil supply flow path 50a and the second back pressure chamber S2 communicate with each other and the second back pressure chamber S2 communicates with the intermediate pressure chamber V, as in the present embodiment.

Thus, the first oil supply passage 371 is formed with a first convolution passage 371a formed to an intermediate position in the thickness direction on the lower surface of the second end plate 331, a second convolution passage 371b formed on the first convolution passage 371a toward the outer peripheral surface of the second end plate 331, and a third convolution passage 371c formed on the second convolution passage 371b toward the upper surface of the second end plate 331.

The first swirl passage portion 371a is formed at a position belonging to the first back pressure chamber S1, and the third swirl passage portion 371c is formed at a position belonging to the second back pressure chamber S2. A pressure reducing rod 375 is inserted into the second swirling passage 371b to reduce the pressure of the oil moving from the first back pressure chamber S1 to the second back pressure chamber S2 through the first oil supply passage 371. Thus, the cross-sectional area of the second convolution path portion 371b of the decompression bar 375 is smaller than the first convolution path portion 371a, the third convolution path portion 371c, or the second convolution path portion 371 b.

At this time, when the end of the third swirl passage portion 371c is positioned inside the cross ring 35, that is, between the cross ring 35 and the seal member 36, the cross ring 35 blocks the oil moving through the first oil supply passage 371, and the oil cannot smoothly move to the second back pressure chamber S2. Thus, in this case, the fourth swirl passage portion 371d may be formed from the end of the third swirl passage portion 371c toward the outer peripheral surface of the second end plate portion 331. As shown in fig. 4, the fourth convolution path 371d may be a groove formed in the upper surface of the second end plate 331 or may be a hole formed in the second end plate 331.

The second oil supply passage 372 has a first fixed passage portion 372a formed in the thickness direction on the upper surface of the second side wall portion 322, a second fixed passage portion 372b formed in the first fixed passage portion 372a in the radial direction, and a third fixed passage portion 372c formed in the second fixed passage portion 372b so as to communicate with the intermediate pressure chamber V.

The drawing, not labeled 70, is a reservoir.

the lower compression scroll compressor of the present embodiment as described above operates as follows.

that is, when power is applied to the power transmission unit 20, a rotational force is generated between the rotor 22 and the rotary shaft 50 to rotate, and the swirling disc 33 eccentrically coupled to the rotary shaft 50 is swirled by the cross 35 as the rotary shaft 50 rotates.

At this time, the refrigerant supplied from the outside of the cover body 10 through the refrigerant suction pipe 15 flows into the compression chamber V, and as the volume of the compression chamber V decreases due to the swirling motion of the swirling scroll 33, the refrigerant is compressed and discharged to the internal space of the discharge cover 34 through the discharge ports 325a and 325 b.

At this time, the refrigerant discharged into the internal space of the discharge cap 34 circulates through the internal space of the discharge cap 34, the noise is reduced, and the refrigerant moves to the space between the frame 31 and the stator 21, and the refrigerant moves to the upper space of the power transmission unit 20 through the gap between the stator 21 and the rotor 22.

At this time, after oil is separated from the refrigerant in the upper space of the power transmission unit 20, the refrigerant is discharged to the outside of the cover 10 through the refrigerant discharge pipe 16, and a series of processes in which the oil is repeatedly collected to the lower space 10c, which is the oil storage space of the cover 10, through the flow path between the inner circumferential surface of the cover 10 and the stator 21 and through the flow path between the inner circumferential surface of the cover 10 and the outer circumferential surface of the compression unit 30 are repeated.

at this time, the oil in the lower space 10c is sucked up through the oil supply passage 50a of the rotary shaft 50, and the oil lubricates the first bearing portion 51, the second bearing portion 52, and the eccentric portion 53 through the respective supply holes 511, 521, and 531 and the supply grooves 512, 522, and 532.

the oil lubricated the first bearing part 51 by the first oil supply hole 511 and the first oil supply groove 512 is collected in the first connection groove 541 between the first bearing part 51 and the eccentric part 53, and flows into the first back pressure chamber S1. The oil almost forms the discharge pressure and the pressure of the first back pressure chamber S1 also almost forms the discharge pressure. Therefore, the center portion side of the second scroll 33 can be axially supported by the discharge pressure.

On the other hand, the oil of the first back pressure chamber S1 moves to the second back pressure chamber S2 through the first oil supply passage 371 by a pressure difference with the second back pressure chamber S2. Here, a pressure reducing rod 375 is provided in the second convolution path portion 371b constituting the first oil supply path 371, and the pressure of the oil heading to the second back pressure chamber S2 is reduced to an intermediate pressure.

The oil that has moved to the second back pressure chamber (intermediate pressure space) S2 moves to the intermediate pressure chamber V through the second oil supply passage 372 by the pressure difference with the intermediate pressure chamber V while supporting the edge portion of the second scroll 33. However, when the pressure of the intermediate pressure chamber V becomes higher than the pressure of the second back pressure chamber S2 during operation of the compressor, the refrigerant moves from the intermediate pressure chamber V to the second back pressure chamber S2 through the second oil supply passage 372. That is, the second oil supply passage 372 functions as a passage through which the refrigerant and the oil cross each other according to the pressure of the second back pressure chamber S2 and the pressure difference of the intermediate pressure chamber V.

On the other hand, as described above, the back pressure chamber is formed on the back surface of the second scroll, that is, the upper surface of the second scroll, and prevents the second scroll from being pushed away from the first scroll by the pressure of the compression chamber.

That is, in the back pressure chamber, the lower surface of the frame and the upper surface of the second scroll are provided with the sealing member, so that the first back pressure chamber can be formed between the second scroll and the frame, and the second back pressure chamber can be formed between the second scroll and the frame and between the second scroll and the first scroll.

therefore, the seal member is preferably a seal member that has good sealing ability between the frame and the second scroll and has good wear resistance in consideration of friction generated by the orbiting motion of the second scroll. Further, the seal member is preferably formed of a material and a structure that can be quickly floated even at a low pressure because the seal member can be floated by pressure and sealed in a state of being inserted into the seal member insertion groove of the second scroll.

On the other hand, as described above, as the discharge pressure is formed in the first back pressure chamber which is the central portion of the second scroll and the intermediate pressure is formed in the second back pressure chamber which is the peripheral portion, the back pressure at the central portion of the second scroll which is the swirl scroll is larger than the back pressure at the peripheral portion. Accordingly, the center portion of the second scroll is pressed more toward the first scroll than the edge portion, and thus the discharge end of the first wrap portion located at the center portion of the first scroll excessively adheres to the second end plate portion. At the same time, the center portion of the first spiral part receives a discharge pressure by forming a discharge end, and the discharge end of the first spiral part receives a strong air pressure in the direction of the edge position according to the discharge pressure.

Accordingly, the discharge end of the first scroll portion receives a force pressing the center portion of the second scroll in the axial direction by the high back pressure of the first back pressure chamber and a force pushing in the radial direction by the gas pressure of the discharge pressure, and finally, the discharge end of the first scroll portion can be bent outward from the root of the wrap portion toward the tip end surface side of the wrap portion, that is, in the height direction of the wrap portion.

This phenomenon is further serious when a second support hole through which the rotation shaft penetrates is formed in the center of the first scroll as the fixed scroll as in the present embodiment. Namely, this is because of the following reasons: when the second support hole is formed at the center of the first scroll, the discharge end of the first scroll portion, which is the fixed scroll portion, cannot be extended to the center of the first scroll due to the second support hole, and thus the discharge end of the first scroll portion is disposed away from the center portion of the scroll, and the rigidity of the lap portion at the discharge end is accordingly lowered, thereby increasing the deformation of the lap portion.

Further, this phenomenon is more serious when the compression ratio is increased by changing the first wrap portion and the second wrap portion to atypical shapes as in the present embodiment. However, in the present embodiment, although the spiral part supporting force is increased to some extent by forming the convex portion at the discharge end of the first spiral part, the spiral part supporting force is not increased in accordance with an increase in the compression ratio, and there is a possibility that a friction loss or abrasion due to deformation of the spiral part or a breakage of the spiral part may occur at the discharge end of the first spiral part. Fig. 5 is a schematic view showing the deformation amount of the discharge end peripheral portion of the first scroll portion analyzed and shown for each portion, and fig. 6 is a schematic view showing the scroll portion shape in the portion having the largest deformation amount in fig. 5 in front.

as shown in fig. 5, in the case of the first spiral part 323, the deformation amount of the discharge end 323a is approximately 0.018mm to 0.02mm at the maximum, and gradually decreases from the discharge end 323a toward the suction end. Further, it can be seen that the deformation amount of the first end plate portion 321 including the periphery of the discharge end 323a of the first spiral part 323 is approximately about-0.003 mm to-0.005 mm. This may be considered as a case where the first end plate 321 is slightly deformed by a force in a direction opposite to the deformation of the first spiral part 323.

As a result, as shown in fig. 6, the tip end surface of the periphery of the discharge end 323a is pneumatically bent to the right in the figure, that is, from the center portion toward the edge portion, so that the inner side corner 323a1 of the discharge end 323a has the highest point and faces the lower surface of the second end plate portion 331.

At the same time, the second scroll is pressed and moved in the downward direction of the figure by the back pressure. However, as the discharge end 323a of the first scroll portion 323 is deformed to be bent outward, the discharge end 323a of the first scroll portion 323 and the lower surface 331b of the second scroll portion 331 come into contact with each other before the upper surface 321b of the first end plate portion 321 and the distal end surface 332c of the second scroll portion 332 are brought into contact with each other by the back pressure. That is, the interval t1 between the upper surface of the first end plate 321 and the leading end surface 332c of the second end plate 332 is greater than the interval t2 between the discharge end 323a of the first end plate 323 and the lower surface 331b of the second end plate 331. Therefore, in the process of eliminating the interval t2 between the leading end surface 323c of the first scroll portion 323 and the lower surface 331b of the second end plate portion 331 due to the back pressure, the friction loss or wear as described above occurs between the upper surface 321b of the first end plate portion 321 and the leading end surface 332c of the second scroll portion 332, and the vicinity of the discharge end of the first scroll portion is broken.

Therefore, in the present embodiment, by optimizing the rigidity of the wrap in the vicinity of the discharge end, even if the wrap receives an axial force due to a back pressure and a radial force due to a gas pressure, the deformation of the wrap caused by the axial force and the radial force can be minimized, thereby suppressing the friction loss or the wear between the wrap and the end plate portion or the breakage of the wrap.

The first wrap portion of the present embodiment can be realized by having a range in which the wrap portion near the discharge end is formed to have a rigidity coefficient defined as follows, satisfying an optimum limit range.

That is, referring to fig. 7, the stiffness coefficient a of the vicinity of the discharge end of the first wrap (hereinafter, the wrap central portion) may be defined as a first value obtained by dividing the average height h of the wrap central portion section by the average thickness t of the wrap central portion section, and a second value obtained by multiplying the first value by the average radius of curvature R which is the distance between the center of the rotation axis of the wrap central portion section (i.e., the center of the second support hole) and the center line of the first wrap, and the reciprocal of the second value is the stiffness coefficient. At this time, the height of the first scroll part 323 is formed such that the height of the scroll part gradually decreases from the suction end toward the discharge end, and the height of the scroll part in the central section of the scroll part varies with the traveling direction of the scroll part. Accordingly, in order to accurately calculate the height of the wrap portion in the corresponding section (the wrap portion center section), it is preferable to calculate and substitute the average height of the wrap portion as described above. However, since the difference in the wrap height is extremely small, the difference can be ignored and generalized to the wrap height. For the same reason, the radius of curvature of the lap may be generalized to the radius of curvature of the lap. For reference, the curvature radius of the wrap portion is approximately 10 to 20 mm.

That is, this is expressed by the formula (1) as follows.

A ═ 1/((h/t) × R) - - - - - - - - - - -, formula (1)

This value can be multiplied by an arbitrary value of 1000 mm.

However, as described above, the height and thickness of the wrap portion may be defined as the average wrap portion height, the average wrap portion thickness, and the average curvature radius in a certain section, but in some cases, the height, thickness, and curvature radius of the wrap portion may be defined as the wrap portion height, thickness, and curvature radius of the wrap portion at a certain specific point with respect to the traveling direction of the wrap portion. However, it is generally advantageous to define each element based on a fixed interval.

For example, in the case of the present embodiment, if the section in which the largest amount of deformation of the wrap occurs is 0 to 60 ° (where 0 ° is the discharge end), the stiffness coefficient can be calculated using the average height and the average thickness of the wrap between 0 to 60 °, more precisely, between 0 to 45 °, which is the corresponding section.

In this case, the range of the rigidity factor a limited by the corresponding section is preferably about 0.005 or more. That is, when the stiffness coefficient is obtained by referring to the above formula (1), h/t does not exceed about 10. Generally, when the value obtained by dividing the average height of the wrap by the average thickness of the wrap is greater than 10, the wrap height is too high compared to the wrap thickness, so that the wrap rigidity becomes very weak and the wrap is broken. Therefore, h/t should preferably be 10 or less. The thickness of the wrap portion is larger than the height of the wrap portion, and therefore, the rigidity thereof is increased, and it is not necessary to limit the minimum value.

In addition, the average curvature radius of the scroll part is about 10 to 20 mm. The smaller the curvature radius of the wrap portion, the more rigid the wrap portion increases, and in this case, it is not always necessary to limit the case where the curvature radius of the wrap portion is small. Therefore, when the average radius of curvature of the lap is 20mm and the above formula (1) is substituted, the rigidity coefficient a is 1/(10 × 20). Therefore, the rigidity factor was 0.005mm, and the rigidity factor was 5 by multiplying the value by an arbitrary value of 1000 mm. This corresponds to the minimum stiffness coefficient, and therefore, it is preferable that the limited range of the stiffness coefficient with respect to the discharge end of the spiral portion be 5 or more.

Further, the appropriate wrap shape of the discharge end can be determined based on the limited range of the stiffness coefficient. Fig. 8 is a graph for analyzing the amount of wrap deformation based on various specifications and operating speeds of the first wrap.

as shown in the figure, the scroll deformation amount is 20 μm in the case of sample (i), 31 μm in the case of sample (ii), 79 μm in the case of sample (iii), 60 μm in the case of sample (iv), and about 67 μm in the case of sample (iv).

Among these samples, it can be seen that the vicinity of the discharge end of the scroll portion is broken in the sample (c) and the sample (c) in which the amount of deformation of the scroll portion is relatively large, while the vicinity of the discharge end of the scroll portion is maintained in a state of not being broken in the remaining samples (c), and (c). Therefore, a line connecting the sample (c) and the sample (c) can be defined as a limit, and the scroll rigidity of the right-hand scroll portion to which the scroll portion deformation belongs can be restricted with reference to the limit.

In this case, when the limit is referred to FIG. 8, the slope of the limit is in the range of about 0.0001 to 0.0003 and the offset is in the range of 7.0000 to 8.0000. Therefore, the rigidity coefficient is preferably at least greater than [ (0.0001 to 0.0003) × (wrap load by air pressure (N) + (7.000 to 8.0000) ]. More precisely, the stiffness coefficient should be larger than [0.0002 × wrap load (N) +7.5202 due to air pressure ].

On the other hand, in the present embodiment, the limited range of the stiffness coefficient for optimizing the stiffness with respect to the lap near the discharge end of the first lap is analyzed, but the present invention is also applicable to other sections of the first lap (or the second lap). However, since there is a possibility that the limit corresponding to the other section of the first wrap (or the second wrap) is different, the limit range of the stiffness coefficient of the section may be defined by the limit range newly calculated.

As described above, by optimizing the rigidity of the wrap portion of the portion adjacent to the discharge end of the first wrap portion (or the second wrap portion), as shown in fig. 9, the deformation of the wrap portion of the discharge end on the center portion side which is subjected to relatively high back pressure and air pressure (and centrifugal force) can be minimized as compared with the conventional case (shown by the broken line), thereby preventing the first wrap portion 323 from excessively adhering to the second end plate portion 331 of the facing second scroll 33, and reducing friction or wear between the first wrap portion 323 and the second end plate portion 331 (or between the second wrap portion and the first end plate portion) to improve the compressor efficiency.

Further, by optimizing the rigidity of the lap of the portion adjacent to the discharge end of the first scroll part 323 (or the second scroll part), the central portion side discharge end of the first scroll part 323 (or the second scroll part) is suppressed from being bent and deformed in the radial direction, and by this, leakage between the compression chambers V1, V2 is suppressed, whereby the compressor efficiency is improved, and the discharge end of the scroll part is suppressed from being broken, thereby improving the reliability of the compressor.

Even when the rotation shaft 50 penetrates the center portion of the first scroll 32 and the discharge end of the first scroll 323 is away from the center of the first scroll 32, the rigidity of the lap portion of the portion adjacent to the discharge end is optimized, so that the friction or wear between the first scroll 323 (or the second scroll) and the corresponding second end plate portion 331 or the deformation or rupture of the fixed scroll can be prevented, and the efficiency and reliability of the compressor can be improved.

Claims

1. A scroll compressor, comprising:

A first scroll part having a discharge end provided at a central portion thereof, a suction end provided at an edge portion thereof, and a plurality of curved lines connecting the discharge end to the suction end; and

A second scroll part having a discharge end provided at a central portion thereof, a suction end provided at an edge portion thereof, a plurality of curved lines connecting the discharge end to the suction end, and a rotation shaft coupling portion formed at the discharge end so that a rotation shaft is overlapped with and coupled to the first scroll part, the second scroll part engaging with the first scroll part and performing a swirling motion with respect to the first scroll part to form a compression chamber moving toward the central portion together with the first scroll part,

A specific section of at least one of the first wrap and the second wrap is formed by a stiffness coefficient defined as follows:

The average height of the wrap portion in the specific section is divided by the average thickness of the wrap portion to obtain a first value, the first value is multiplied by the average radius of curvature of the wrap portion to obtain a second value, and the inverse of the second value is used to define the stiffness coefficient.

2. the scroll compressor of claim 1,

The limited range of the stiffness coefficient is more than the limit limited range defined by [ (0.0001-0.0003) x scroll load (N) + (7.0000-8.0000) ].

3. The scroll compressor of claim 2,

The limit range is defined by [0.0002 × scroll load (N) +7.5202 ].

4. The scroll compressor of claim 2,

When the center portion side of the first scroll part is set as a discharge end and the discharge end is set as 0 DEG with reference to the rotation angle of the rotation shaft,

The specific interval is in the range of 0-45 degrees based on the rotation angle of the rotating shaft.

5. The scroll compressor of any one of claims 1 to 4,

a circular arc compression surface is formed on one side of the rotating shaft combination part,

A recessed portion in which the thickness of the second wrap portion is reduced is formed in a section between the arc compression surface and the outer side surface of the rotating shaft coupling portion, a projection portion that engages with the recessed portion of the second wrap portion is formed in a section near the discharge end of the first wrap portion,

at least a part of the section forming the convex portion satisfies the range of the rigidity coefficient.

6. A scroll compressor, comprising:

a first scroll including a first end plate portion having a support hole through which the rotating shaft passes at a center portion thereof, a discharge port formed at a periphery of the support hole, and a first scroll portion formed to protrude from one side surface of the first end plate portion; and

A second scroll including a second end plate portion and a second scroll portion, the second end plate portion having a rotation shaft coupling portion formed at a central portion thereof so as to be eccentrically coupled to a rotation shaft penetrating a support hole of the first scroll, the second scroll portion being formed to protrude from one side surface of the second end plate portion and engaged with the first scroll portion to form a compression chamber,

The first scroll part is formed so that the range of the rigidity coefficient defined below is 0.005mm or more,

The rigidity coefficient is defined by the inverse of a value obtained by dividing the wrap height of the first wrap by the wrap thickness and multiplying the value by the curvature radius of the first wrap.

7. The scroll compressor of claim 6,

The limited range of the stiffness coefficient is defined for an interval between any two points in the first wrap portion along the traveling direction of the wrap portion,

The scroll height, the scroll thickness and the scroll curvature radius are defined by the average scroll height, the average scroll thickness and the average scroll curvature radius of the corresponding sections.

8. The scroll compressor of claim 6,

the limited range of the stiffness coefficient is defined for a certain point in the first scroll part,

The scroll height, the scroll thickness and the scroll curvature radius are defined by the scroll height, the scroll thickness and the scroll curvature radius of the corresponding points.

9. The scroll compressor of claim 7 or 8,

in a section from an end portion of the first scroll portion adjacent to the discharge port to a certain point or in a certain point of the section, the limited range of the stiffness coefficient is formed to be equal to or more than a limit limited range defined by [ (0.0001 to 0.0003) × scroll portion load (N) + (7.0000 to 8.0000) ].

10. A scroll compressor, comprising:

a cover body storing oil in an internal space;

A driving motor disposed in the inner space of the cover;

a rotating shaft coupled with the driving motor;

A frame provided at a lower side of the driving motor;

A first scroll provided at a lower side of the frame, having a first scroll portion formed at one side surface thereof, having a support hole formed at a center thereof through which the rotary shaft passes, and having a discharge port formed at a periphery of the support hole; and

A second scroll in which a second wrap portion meshing with the first wrap portion is formed, the rotary shaft being eccentrically coupled to the second wrap portion so as to radially overlap the second wrap portion, the second scroll performing a orbiting motion with respect to the first scroll to form a compression chamber with the first scroll; and

a sealing member disposed between the frame and the second scroll to separate an interval between the frame and the second scroll into an inner interval as a center side and an outer interval as an edge side so that oil sucked up by the rotation shaft flows into the inner interval to form a back pressure chamber,

The first scroll part is formed so that the range of the rigidity coefficient defined below is 5 or more,

The rigidity coefficient is defined by dividing the average wrap height by the average wrap thickness between the first wrap and a first point from the end portion on the side adjacent to the discharge port, and multiplying the inverse of the value obtained by multiplying the average wrap curvature radius by an arbitrary value 1000 mm.

11. The scroll compressor of claim 10,

12. The scroll compressor of claim 11,

The limit range is defined by [0.0002 × scroll load (N) +7.5202 ].

13. The scroll compressor of claim 10,

The first point is a point within a range of 0 to 60 degrees with reference to a rotation angle of the rotating shaft.

14. The scroll compressor of claim 10,

At least a part of the section forming the convex portion satisfies a limited range of the rigidity coefficient.